//    Copyright 2010 Daniel James Kotowski
//
//    This file is part of A9Cipher.
//
//    A9Cipher is free software: you can redistribute it and/or modify
//    it under the terms of the GNU Lesser General Public License as published by
//    the Free Software Foundation, either version 3 of the License, or
//    (at your option) any later version.
//
//    A9Cipher is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//    GNU Lesser General Public License for more details.
//
//    You should have received a copy of the GNU Lesser General Public License
//    along with A9Cipher.  If not, see <http://www.gnu.org/licenses/>.

package com.a9development.a9cipher;

/**
 * The textbook being used gave this example:<br>
 * Plaintext:  0123456789abcdeffedcba9876543210<br>
 * Key:        0f1571c947d9e8590cb7add6af7f6798<br>
 * Ciphertext: ff0b844a0853bf7c6934ab4364148fb9
 * 
 * @author Daniel Kotowski
 * @version 1.0.0
 */

@Deprecated
public class RijndaelCipher {
	private byte[] rijndaelKey;
	private static final String ALGORITHM = "Rijndael";
	
	private static final int[][] rijndaelSBox = {
		{0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76},
		{0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0},
		{0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15},
		{0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75},
		{0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84},
		{0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf},
		{0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8},
		{0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2},
		{0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73},
		{0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb},
		{0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79},
		{0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08},
		{0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a},
		{0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e},
		{0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf},
		{0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16}};
	private static final int[][] rijndaelInverseSBox = {
		{0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb},
		{0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb},
		{0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e},
		{0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25},
		{0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92},
		{0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84},
		{0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06},
		{0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b},
		{0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73},
		{0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e},
		{0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b},
		{0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4},
		{0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f},
		{0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef},
		{0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61},
		{0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d}};
	private int[] rijndaelRCon = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36};
	private int[][] rijndaelMixColumnsMatrix = {
			{0x02, 0x03, 0x01, 0x01},
			{0x01, 0x02, 0x03, 0x01},
			{0x01, 0x01, 0x02, 0x03},
			{0x03, 0x01, 0x01, 0x02}};
	private int[][] rijndaelInverseMixColumnsMatrix = {
			{0x0e, 0x0b, 0x0d, 0x09},
			{0x09, 0x0e, 0x0b, 0x0d},
			{0x0d, 0x09, 0x0e, 0x0b},
			{0x0b, 0x0d, 0x09, 0x0e}};
	             
	public RijndaelCipher(byte[] key) throws Exception {
		if (key.length != 16) {
			// Currently only supports 128-bit keys. Will be expanded in a future version
			throw new Exception("Key must be 16, 24, or 32 ints long");
		} else {
			rijndaelKey = key.clone();
		}
	}
	
	public byte[] encrypt(byte[] plaintext) throws Exception {
		if (plaintext.length != 16) {
			throw new Exception("plaintext must be 16 ints long");
		} else {
			byte[] ciphertext = new byte[16];
			int[][] ctMatrix = new int[4][4];
			int[][] ptMatrix = new int[4][4];
			for (int i = 0; i < 4; i++) {
				ptMatrix[i][0] = plaintext[4*i];
				ptMatrix[i][1] = plaintext[4*i + 1];
				ptMatrix[i][2] = plaintext[4*i + 2];
				ptMatrix[i][3] = plaintext[4*i + 3];
			}
			int[][][] rijndaelRKeys = rijndaelMakeRoundKeys(rijndaelKey);
			ctMatrix = rijndaelAddRoundKey(ptMatrix, rijndaelRKeys[0]);
			for (int i = 1; i < 10; i++) {
				ctMatrix = rijndaelAddRoundKey(rijndaelMixColumns(rijndaelShiftRows(rijndaelSubints(ctMatrix))), rijndaelRKeys[i]);
			}
			ctMatrix = rijndaelAddRoundKey(rijndaelShiftRows(rijndaelSubints(ctMatrix)), rijndaelRKeys[10]);
			for (int i = 0; i < 4; i++) {
				ciphertext[4*i] = (byte) (ctMatrix[i][0] & 0xffff);
				ciphertext[4*i + 1] = (byte) (ctMatrix[i][1] & 0xffff);
				ciphertext[4*i + 2] = (byte) (ctMatrix[i][2] & 0xffff);
				ciphertext[4*i + 3] = (byte) (ctMatrix[i][3] & 0xffff);
			}
			return ciphertext;
		}
	}
	
	public byte[] decrypt(byte[] ciphertext) throws Exception {
		if (ciphertext.length != 16) {
			throw new Exception("ciphertext must be 16 ints long");
		} else {
			byte[] plaintext = new byte[16];
			int[][] ptMatrix = new int[4][4];
			int[][] ctMatrix = new int[4][4];
			for (int i = 0; i < 4; i++) {
				ctMatrix[i][0] = ciphertext[4*i];
				ctMatrix[i][1] = ciphertext[4*i+1];
				ctMatrix[i][2] = ciphertext[4*i+2];
				ctMatrix[i][3] = ciphertext[4*i+3];
			}
			int[][][] rijndaelRKeys = rijndaelMakeRoundKeys(rijndaelKey);
			ptMatrix = rijndaelAddRoundKey(ctMatrix, rijndaelRKeys[10]);
			for (int i = 9; i > 0; i--) {
//				ptMatrix = rijndaelInverseMixColumns(rijndaelAddRoundKey(rijndaelInverseSubints(rijndaelInverseShiftRows(ptMatrix)), rijndaelRKeys[i]));
				ptMatrix = rijndaelInverseShiftRows(ptMatrix);
				ptMatrix = rijndaelInverseSubints(ptMatrix);
				ptMatrix = rijndaelAddRoundKey(ptMatrix, rijndaelRKeys[i]);
				ptMatrix = rijndaelInverseMixColumns(ptMatrix);
			}
			ptMatrix = rijndaelAddRoundKey(rijndaelInverseSubints(rijndaelInverseShiftRows(ptMatrix)), rijndaelRKeys[0]);
			for (int i = 0; i < 4; i++) {
				plaintext[4*i] = (byte) (ptMatrix[i][0] & 0xffff);
				plaintext[4*i+1] = (byte) (ptMatrix[i][1] & 0xffff);
				plaintext[4*i+2] = (byte) (ptMatrix[i][2] & 0xffff);
				plaintext[4*i+3] = (byte) (ptMatrix[i][3] & 0xffff);
			}
			return plaintext;
		}
	}

	private int[][] rijndaelSubints (int[][] B) throws Exception {
		if (B.length != 4 || B[0].length != 4) {
			throw new Exception("B must be 4x4 ints");
		} else {
			int[][] subbed = new int[4][4];
			for (int i = 0; i < 4; i++) {
				for (int j = 0; j < 4; j++) {
					subbed[i][j] = rijndaelSBox[(B[i][j] >> 4) & 0x0f][B[i][j] & 0x0f];
				}
			}
			return subbed;
		}
	}
	
	private int[][] rijndaelInverseSubints (int[][] B) throws Exception {
		if (B.length != 4 || B[0].length != 4) {
			throw new Exception("B must be 4x4 ints");
		} else {
			int[][] subbed = new int[4][4];
			for (int i = 0; i < 4; i++) {
				for (int j = 0; j < 4; j++) {
					int r = (B[i][j] & 0xF0) >>> 4;
					int c = B[i][j] & 0xF;
					subbed[i][j] = rijndaelInverseSBox[r][c];
//					subbed[i][j] = rijndaelInverseSBox[B[i][j] >>> 4][B[i][j] % 16];
				}
			}
			return subbed;
		}
	}
	
	private int[][] rijndaelShiftRows (int[][] B) throws Exception {
		if (B.length != 4 || B[0].length != 4) {
			throw new Exception("B must be 4x4 ints");
		} else {
			int[][] shifted = new int[4][4];
			for (int i = 0; i < 4; i++) {
				for (int j = 0; j < 4; j++) {
					shifted[i][j] = B[(i+j)%4][j];
				}
			}
			return shifted;
		}
	}
	
	private int[][] rijndaelInverseShiftRows (int[][] B) throws Exception {
		if (B.length != 4 || B[0].length != 4) {
			throw new Exception("B must be 4x4 ints");
		} else {
			int[][] shifted = new int[4][4];
			for (int i = 0; i < 4; i++) {
				for (int j = 0; j < 4; j++) {
					shifted[i][j] = B[(4+i-j)%4][j];
				}
			}
			return shifted;
		}
	}
	
	private int[][] rijndaelMixColumns (int[][] B) throws Exception {
		if (B.length != 4 || B[0].length != 4) {
			throw new Exception("B must be 4x4 ints");
		} else {
			int[][] mixed = new int[4][4];
			for (int i = 0; i < 4; i++) {
				for (int j = 0; j < 4; j++) {
					for (int k = 0; k < 4; k++) {
						mixed[j][i] ^= rijndaelGFMult(rijndaelMixColumnsMatrix[i][k], B[j][k]);
					}
				}
			}
			return mixed;
		}
	}
	
	private int[][] rijndaelInverseMixColumns (int[][] B) throws Exception {
		if (B.length != 4 || B[0].length != 4) {
			throw new Exception("B must be 4x4 ints");
		} else {
			int[][] mixed = new int[4][4];
			for (int i = 0; i < 4; i++) {
				for (int j = 0; j < 4; j++) {
					for (int k = 0; k < 4; k++) {
						mixed[j][i] ^= rijndaelGFMult(rijndaelInverseMixColumnsMatrix[i][k], B[j][k]);
					}
				}
			}
			return mixed;
		}
	}
	
	private int[][] rijndaelAddRoundKey (int[][] B, int[][] roundKey) throws Exception {
		if (B.length != 4 || B[0].length != 4) {
			throw new Exception("B must be 4x4 ints");
		} else if (roundKey.length != 4 || roundKey[0].length != 4) {
			throw new Exception("roundKey must be 4x4 ints");
		} else {
			int[][] keyed = new int[4][4];
			for (int i = 0; i < 4; i++) {
				for (int j = 0; j < 4; j++) {
					keyed[i][j] = (B[i][j] ^ roundKey[i][j]);
				}
			}
			return keyed;
		}
	}
	
	private int[] rijndaelSubWord(int[] W) throws Exception {
		if (W.length != 4) {
			throw new Exception("W must be 4 ints");
		} else {
			int[] subbed = new int[4];
			for (int i = 0; i < 4; i++) {
				subbed[i] = rijndaelSBox[(W[i] >> 4) & 0x0f][W[i] & 0x0f];
			}
			return subbed;
		}
	}
	
	private int[] rijndaelRotWord(int[] W) throws Exception {
		if (W.length != 4) {
			throw new Exception("W must be 4 ints");
		} else {
			int[] rotted = new int[4];
			rotted[0] = W[1];
			rotted[1] = W[2];
			rotted[2] = W[3];
			rotted[3] = W[0];
			return rotted;
		}
	}
	
	private int[][][] rijndaelMakeRoundKeys (byte[] key) throws Exception {
		if (key.length != 16) {
			throw new Exception("key must be 16 ints long");
		} else {
			int[][] w = new int[44][4];
			int[][][] rijndaelRoundKeys = new int[11][4][4];
			for (int i = 0; i < 4; i++) {
				for (int j = 0; j < 4; j++) {
					w[i][j] = key[4*i + j];
				}
			}
			int[] temp = new int[4];
			for (int i = 4; i < 44; i++) {
				temp = w[i-1];
				if ((i % 4) == 0) {
					temp = rijndaelRotWord(temp);
					temp = rijndaelSubWord(temp);
					temp[0] = (temp[0] ^ rijndaelRCon[(i/4) - 1]);
				}
				for (int j = 0; j < 4; j++) {
					w[i][j] = (w[i-4][j] ^ temp[j]);
				}
			}
			for (int i = 0; i < 11; i++) {
				for (int j = 0; j < 4; j++) {
					rijndaelRoundKeys[i][j] = w[4*i + j]; 
				}
			}
			return rijndaelRoundKeys;
		}
	}	
	
	public static int rijndaelGFMult(int a, int b) {
		int p = 0;
		boolean doXor;
		for (int i = 0; i < 8; i++) {
			if ((a & 1) == 1)
				p ^= b;
			doXor = ((b & 0x80) == 0x80);
			b = (b * 2) & 0xff;
			if (doXor)
				b ^= 0x1b;
			a >>>= 1;
		}
		return p;
	}
		
	public byte[] getRijndaelKey() {
		return rijndaelKey;
	}

	public void setRijndaelKey(byte[] rijndaelKey) {
		this.rijndaelKey = rijndaelKey;
	}
	
	public String getAlgorithm() {
		return ALGORITHM;
	}

}
